Biomedical subjects

N Ikeda

Publications and source records attributed to N Ikeda.

At least 109 records · Page 6Linked to original sources

PubMed1999

Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions.

The surface tensions of aqueous salt solutions of LiCl, KCl, and CsCl were measured as a function of concentration and temperature. By analyzing the results, the thermodynamic quantities of surface formation such as entropy (Deltas), Helmholtz free energy (Deltaf), and energy of surface formation (Deltau) were evaluated. Addition of salts into aqueous solution leads to an increase in Deltaf but decreases in Deltas and Deltau. The variations of Deltas, Deltaf, and Deltau with the change of salt concentration are almost the same for all alkali metal chlorides in spite of their large difference in hydration force. Copyright 1999 Academic Press.

Journal Article↗

PubMed1999

Plasma lipids, lipoproteins and apolipoproteins and sudden cardiac death.

To investigate the risk factors for sudden cardiac death, in particular that triggered by coronary heart disease, we analysed 17 different lipids, lipoproteins and apolipoproteins in the plasma of patients who had suffered sudden death, including sudden cardiac death. Studies were carried out on 107 cadavers comprising 78 subjects where the cause of death was diagnosed as sudden cardiac death and 29 subjects diagnosed with other causes of sudden death. All 107 cases were classified into four groups according to the degree of coronary stenosis and the degree of cardiac hypertrophy. Plasma levels of total cholesterol (T-CHOL), triglyceride (TG), beta-lipoprotein (beta-LIPO), free fatty acid, phospholipid, free cholesterol, high density lipoprotein cholesterol, lipoprotein(a) [Lp(a)], lipoproteins (VLDL, LDL, HDL) and apolipoproteins (apoAI, apoAII, apoB, apoCII, apoCIII, apoE) were determined. The level of apoB showed a significant difference and positive correlation with the degree of coronary stenosis by two different statistical methods, while the levels of T-CHOL, TG, beta-LIPO, VLDL, apoCII, apoCIII and apoE showed significant differences with the degree of coronary stenosis by one statistical method. It was concluded that a high plasma level of apoB is a risk factor for coronary stenosis, with higher levels resulting in more severe degrees of coronary stenosis. Furthermore, a significant difference was found regarding only apoCIII both between the sudden cardiac death group and the sudden death from other causes group, and between each of the four groups classified according to the degree of coronary stenosis. It was thus concluded that a high plasma level of apoCIII indicates the possibility of a coronary stenotic origin for sudden cardiac death.

Adult↗

PubMed1999

An operative procedure for advanced Kienböck's disease. Excision of the lunate and subsequent replacement with a tendon-ball implant.

Excision of the lunate and subsequent replacement with a tendon implant was performed in 22 patients with Kienböck's disease between 1971 and 1985. This procedure was indicated mainly for those with advanced Kienböck's disease, i.e., stage III or IV according to the Lichtman classification. After the collapsed lunate is removed, a tendon-ball implant, made of the palmaris longus and plantaris tendons is placed in the resultant space in the carpus. A forearm distractor is applied during the operation, and distraction is continued for 4 weeks postoperatively. We report the long-term results in 15 patients, whose average follow-up period was 16 years and 3 months. One patient with infection was excluded from the study because the implanted tendon was removed 2 weeks after the operation, and 6 patients were lost to follow-up. All patients were free of pain after the surgery. The flexion-extension range of the wrist increased by 14.2 degrees, on average, after the surgery. The average grip power of the operated hand was 90.2% of that in the non-operated hand. Calcification and ossification were frequent in the implanted tendons a few months postoperatively. The average carpal height ratio (defined as carpal height/length of the third metacarpal) was 0.53 before the operation and 0.49 at the time of follow-up. According to Dornan's classification of clinical results, 9 of the 15 patients were classified as having excellent results and 6 as good.

Adult↗

PubMed1999

Evaluation of the staphylococcal exotoxins and their specific IgE in childhood atopic dermatitis.

BACKGROUND: Superantigenic exotoxins produced by Staphylococcus aureus and their specific IgE antibodies are thought to be important precipitating factors of atopic dermatitis (AD), but there are few reports evaluating these 2 factors at the same time. OBJECTIVE: We examined whether the presence of the exotoxins sampled from the skin of patients with AD and the levels of anti-exotoxin IgE antibodies in their sera correlated with their severity of AD. METHODS: Patients with mild-to-severe AD, 1 to 22 years of age, were evaluated by using Leicester's scoring system. Specific IgE antibodies against these exotoxins were determined by using ELISA. S aureus was isolated from 3 different areas of the skin. We examined whether the exotoxin (staphylococcal enterotoxin [SE]A, SEB, SEC, SED, and toxic shock syndrome toxin-1) could be detected. RESULTS: The levels of SEB-specific IgE were correlated with the severity of AD. Five of 6 patients having very high SEB-specific IgE antibody titers were under 6 years of age, and SEB was most frequently isolated (41%). There was no difference in severity between patients with or without exotoxin-producing S aureus. The severity of 9 patients who had both exotoxin-producing S aureus on the skin and specific IgE antibody against the same exotoxin in sera was significantly higher than that of the other patients. CONCLUSIONS: Anti-SEB IgE titers correlate well with the severity of AD. The presence of exotoxin-producing S aureus may precipitate AD through its specific IgE antibody.

Adolescent↗

PubMed1999

Quantitative comparison of osteoconduction of porous, dense A-W glass-ceramic and hydroxyapatite granules (effects of granule and pore sizes).

The osteoconductive potentials of dense, small porous and large porous apatite- and wollastonite-containing glass-ceramic (A-W GC) granules of various sizes implanted in rat tibiae were evaluated quantitatively, by determining their affinity indices. The average affinity indices of all types of A-W GC were high. The dense A-W GC granules had the highest values (97.0+/-5.5%), followed by the large porous (87.1+/-8.4%) and then the small porous granules (79.0+/-8.4%). There were no significant differences among the osteoconductive potentials of the different sizes of each form of A-W GC granule. The osteoconductive potentials of four types of commercially available porous hydroxyapatite (HA) granules were compared with those of the small porous A-W GC granules, using the affinity index and the proportion of newly formed bone relative to that of the granules in the bone defect. The values of the former parameter for three types of HA and those of the latter for four were significantly inferior to those of A-W GC. The difference between the osteoconductive potentials of A-W GC and HA was considered to be related to the rate of surface apatite layer formation.

Animals↗

PubMed1999

Identification of an alcoholic beverage in which methamphetamine was dissolved.

A man was arrested for violating the Stimulant Control Law. Twelve small plastic containers each containing 1-3 ml of reddish purple alcoholic beverage in which methamphetamine had been dissolved, and a bottle of blueberry liquor of a similar colour, were found in his house. He admitted that the blueberry liquor belonged to him, but strongly insisted that he had been asked to keep the containers by another person and that he had no knowledge of their contents. The alcoholic beverage and the blueberry liquor were analyzed in order to test whether he had dissolved methamphetamine in the blueberry liquor. The aroma components found in the alcoholic beverage in each of the plastic containers were identical, but differed from those found in the blueberry liquor. Based on these results and further police investigations, the suspect's allegation was supported and he was not prosecuted.

Journal Article↗

PubMed1999

Death attributed to amobarbital and levomepromazine intoxication.

A 29-year-old man, possibly a schizophrenic patient, was found dead 9 h after admission to a hospital. Autopsy revealed neither significant injuries nor diseases except for congestion of all organs. Microscopic examination revealed severe edema in the lung and slight centrilobular necrosis in the liver. Since amobarbital and levomepromazine were detected by drug screening, the concentrations of these drugs in the victim's body fluids and tissues were determined using gas chromatography-mass spectrometry. The whole blood concentrations of amobarbital and levomepromazine were 9.02 microg/ml and 231 ng/ml, respectively. These levels exceeded therapeutic ranges, but are not so toxic or fatal. However, on the basis of the findings in the literature and of the severe lung edema and centrilobular necrosis in the liver, the cause of his death was judged to be amobarbital and levomepromazine intoxication.

Journal Article↗

PubMed1999

Ethanol distribution in the brain of a victim autopsied after acute subdural hemorrhage.

We examined ethanol distribution in the brain of a 62-year-old male, who had died of acute subdural hemorrhage 4 days after injury. His blood ethanol concentration was 2.70 mg/g on admission. Blood pressure suddenly decreased and spontaneous respiration ceased 7 h after admission. He was artificially ventilated and died 4 days later. Ethanol was detected in the subdural hematoma, cerebellum, medulla oblongata and all cerebral lobes. Ethanol level in the right parietal lobe was highest; the levels in the right hemisphere of the cerebrum were higher than those in the left. Ethanol levels in the right parietal lobe were almost the same as the blood level calculated 7 h after admission; while the levels in the left parietal lobe and cerebellum were much lower. Thus, it was judged that cerebral blood flow first ceased in the right parietal lobe at 7 h after admission and completely ceased in other regions 11-12 h after. Assessment of ethanol distribution in multiple brain regions seems useful for estimating the time and progression profile of brain death.

Journal Article↗

PubMed1999

Simultaneous determination of triazolam and its metabolites in human blood and urine by gas chromatography/mass spectrometry.

A sensitive and selective method has been developed for simultaneous determination of triazolam and its major metabolites, alpha-hydroxytriazolam and 4-hydroxytriazolam, in human whole blood and urine. The drugs were effectively extracted using a 3-step solvent extraction procedure followed by tert- butyldimethylsilyl derivatization, and subjected to gas chromatography-mass spectrometry in the negative ion chemical ionization mode. Estazolam was used as an internal standard. The calibration curve for each compound was linear in the range from 0.5 to 100 ng/g, and the lower limit of detection was 0.1 ng/g for whole blood and 0.2 ng/g for urine. Within-day precision of this method was evaluated in whole blood and urine samples at the concentration of 10 ng/g; the coefficient of within-day variation ranged from 2.7 to 10.8%.

Journal Article↗

PubMed1999

Sudden unexpected death following stellate ganglion block.

A 29-year-old woman, who had been suffering from left facial palsy, died 3.5 hours after undergoing stellate ganglion block (SGB). Autopsy revealed subcutaneous emphysema of the body, bilateral pneumothorax and a huge post-tracheal hematoma. The lower half of the trachea was markedly flattened by pressure from this hematoma. The cause of death was certified as airway obstruction due to a post-tracheal hematoma following SGB. The doctor cut both the anterior and the posterior wall of the trachea, because the trachea was flattened by the hematoma. He then intubated and sent air into the post-tracheal space. We consider that the patient could have recovered if she had received the correct tracheotomy. We therefore conclude that there was professional error on the part of the doctor in the form of medical malpractice.

Journal Article↗

PubMed1999

Prognostic significance of angiogenesis in human pancreatic cancer.

To evaluate whether angiogenic factors are of clinical relevance to actual human pancreatic cancers, we studied the intratumoral microvessel density (IMD), and PD-ECGF, VEGF protein expression in 40 pancreatic cancers using immunohistochemistry. We also investigated PD-ECGF and VEGF gene expression using reverse transcriptase-PCR (RT-PCR). Of the 40 pancreatic cancers studied, 30 carcinomas (75.0%) were evaluated to be PD-ECGF-positive and 10 carcinomas (25.0%) were determined to be PD-ECGF-negative. In contrast, 27 carcinomas (67.5%) were evaluated to be VEGF-positive, whereas 13 carcinomas (32.5%) were VEGF-negative. VEGF gene expression was moderately associated with an increase in the IMD (r2 = 0.181, P = 0.006), but no significant relationship was found between PD-ECGF gene expression and the IMD (r2 = 0.093, P = 0.059). However, tumours with positive expression for both PD-ECGF and VEGF had a higher IMD (P = 0.027). The results of the immunohistochemistry agreed well with the results of the quantitative RT-PCR. The median survival time of the hypervascular group was significantly shorter than that of the hypovascular group (P < 0.0001). In comparing the survival according to PD-ECGF and VEGF gene expression, the median survival time of the patients with positive PD-ECGF expression was significantly shorter than those with negative PD-ECGF expression (P = 0.040). Furthermore, the median survival time of the patients with positive VEGF expression was significantly shorter than those with negative VEGF expression (P = 0.048). However, the Cox multivariate analysis indicated that the IMD and VEGF expression were independent prognostic factors of the various clinicopathologic variables in pancreatic cancer patients (P = 0.0021 and P = 0.0443, respectively).

Aged↗

PubMed1999

A newly designed adapter for testing an ex vivo mitral valve apparatus.

Few instruments are currently available to test mitral valve function in an ex vivo state due to the technical difficulties involved. To investigate the native ex vivo mitral valve or prosthetic mitral valve with chordae, we developed a mitral valve adapter with an annulus suturing portion and 2 papillary muscle suturing sites that can be changed in angle, direction, and length of chordae. We used this adapter to test an ex vivo mitral apparatus in beagle dogs and evaluated the morphology and function of the mitral apparatus by endoscopy. Our newly designed mitral valve adapter proved extremely useful for examining the ex vivo mitral valve anatomy and function and for testing stentless mitral prostheses with annular-papillary muscle continuity.

Animals↗

PubMed1999

Oral mucosal lesions associated with betel quid, areca nut and tobacco chewing habits: consensus from a workshop held in Kuala Lumpur, Malaysia, November 25-27, 1996.

A variety of betel/areca nut/tobacco habits have been reviewed and categorized because of their possible causal association with oral cancer and various oral precancerous lesions and conditions, and on account of their widespread occurrence in different parts of the world. At a recent workshop in Kuala Lumpur it was recommended that "quid" be defined as "a substance, or mixture of substances, placed in the mouth or chewed and remaining in contact with the mucosa, usually containing one or both of the two basic ingredients, tobacco and/or areca nut, in raw or any manufactured or processed form." Clear delineations on contents of the quid (areca nut quid, tobacco quid, and tobacco and areca nut quid) are recommended as absolute criteria with finer subdivisions to be added if necessary. The betel quid refers to any quid wrapped in betel leaf and is therefore a specific variety of quid. The workshop proposed that quid-related lesions should be categorized conceptually into two categories: first, those that are diffusely outlined and second, those localized at the site where a quid is regularly placed. Additional or expanded criteria and guidelines were proposed to define, describe or identify lesions such as chewer's mucosa, areca nut chewer's lesion, oral submucous fibrosis and other quid-related lesions. A new clinical entity, betel-quid lichenoid lesion, was also proposed to describe an oral lichen planus-like lesion associated with the betel quid habit.

Areca↗

PubMed1999

[In vitro susceptibility of Streptococcus agalactiae clinical isolates to beta-lactam antibiotics].

The susceptibility of Streptococcus agalactiae (S. agalactiae) clinical isolates of Juntendo University Urayasu Hospital, and type strain ATCC 13813 to beta-lactam antimicrobial agents was evaluated by means of macro-broth dilution MIC determination, killing kinetics and population analysis. When 10(6) cells of S. agalactiae were inoculated and cultured in Todd-Hewitt broth containing two-fold serial dilutions of penicillin, the viable cell count showed that about 10(2) cells survived irrespective of the penicillin concentration which ranged from 0.063 to 128 micrograms/ml. The result indicated that S. agalactiae had tolerance to penicillin (MICs were around 0.063 microgram/ml). Furthermore, the S. agalactiae strains were found to have a paradoxical response to penicillin in an acidic condition (pH 5.5). When the cell counts were performed at pH 5.5, about 10(2) cells survived at penicillin concentrations from 0.016 to 0.125 microgram/ml, while about 10(4) cells survived at the concentrations of 1 to 8 micrograms/ml. The antibiotic tolerance and paradoxical effects of S. agalactiae were also observed in killing kinetics. The ATCC 13,813 and 10 out of 11 clinical strains showed slow response to penicillin-mediated killing at pH 7.8 and ATCC 13,813 and one of the clinical strains showed a reduced response with increase in penicillin concentration at pH 5.5. These results suggested that the tolerance and paradoxical effect of S. agalactiae cells to beta-lactam antibiotics may be one of the reasons for frequent re-colonization of S. agalactiae at the time of delivery after the chemophylaxis in the 2nd trimester.

Anti-Bacterial Agents↗

PubMed1999

[An analysis of fever of unknown origin defined by newly proposed practical criteria. A prospective study of 56 cases].

The criteria proposed by Petersdorf has been in use internationally to define the fever of unknown origin (FUO) since 1961 and the research of FUO has progressed with this criteria. Mean-while, new diagnostic methods have been developed and illness behavior of febrile patients has changed considerablly. Accordingly, the definition by Petersdorf is becoming less matched to current clinical situation. Therefore, we have developed a new practical criteria of FUO; i.e., out-patients who are febrile more than 2 weeks, documented temperature higher than 37.5 degrees C at least on one occasion and undetermined diagnosis and in-patients who are febrile more than 1 week with documented temperature higher than 37.5 degrees C, and undetermined diagnosis. Between October 1, 1993, and October 31, 1996, we prospectively collected a series of febrile patients who fulfilled our new criteria. We identified 56 patients by our criteria (23 male and 33 female, age: 49.7 +/- 20.6. range 15 to 88). Of this 56 patients, 19 (32%) were found to have infections, 18 (31%) had collagen disorders, 5 (9%) had malignancy and 6 (10%) had died. Of 56 patients, 38 (68%) were in the newly added group. Of these 38 patients, 4 patients had subacute necrotizing lymphoadenitis, 4 cytomegalovirus infection, 3 polymyalgia rheumatica, 3 tuberculosis. Four patients (10%) died. With our criteria, febrile patients who previously had not been included were found to have as poor a prognosis as with the Petersdorf group.

Adolescent↗

PubMed1999

Vogt-Koyanagi-Harada syndrome in an 11-year-old Boy.

An 11-year-old boy complained of headache, slight fever and decreased visual acuity. Intracameral cells and serous retinal detachment were found in both eyes. Pleocytosis was seen in the cerebrospinal fluid. Bilateral uveitis diminished rapidly in response to corticosteroid treatment. Depigmentation of the fundi developed several months later. We believe that Vogt-Koyanagi-Harada syndrome in a child, as demonstrated in our patient, may be uncommon.

Atropine↗

PubMed1999

Effects of Maillard reaction products on the oxidative cleavage and polymerization of protein under ascorbic acid-transition metal system.

This study investigated the effects of Maillard reaction products (MRPs) on the oxidative cleavage and polymerization of BSA (bovine serum albumin) in an aqueous system. In L-ascorbic acid (AsA) and Cu(II) or Fe(III) reaction system, 50-60% of BSA was cleaved under physiological conditions (37 degrees C, pH 7.2). The oxidative cleavage induced by AsA-Cu(II) system was suppressed to the extent of 32-86% by model melanoidins or brown pigments from amino acids and foodstuffs. In the AsA-Fe(III) system, the oxidative cleavage was inhibited to the extent of 45-93% by melanoidins and brown pigments. However, this cleavage was promoted by amino acid Amadori rearrangement products and brown pigment from soy paste. Therefore, MRPs show both suppression and promotion activity on oxidative cleavage of BSA in the system of AsA and a transition metal. The quantity of Amadori rearrangement moiety (ARM) in melanoidins from Lysine and brown pigments molecules from foods was also measured. From these data, it was estimated that the suppression and/or promotion of oxidative cleavage of BSA did not only depend on the quantity of ARM, but also depended on the chemical structure of ARM in melanoidins or brown pigments.

Ascorbic Acid↗

PubMed1999

Diagnosis of the nutcracker syndrome with color Doppler sonography: correlation with flow patterns on retrograde left renal venography.

OBJECTIVE: Our objective was to confirm flow patterns of the left renal vein and assess the usefulness of color Doppler sonography in the diagnosis of the renal vein entrapment, or nutcracker, syndrome. SUBJECTS AND METHODS: Forty-four patients with hematuria of unknown origin underwent color Doppler sonography, renal arteriography, retrograde left renal venography, and renocaval pressure measurement. The flow patterns were classified according to the presence or absence of distended left renal veins on sonograms and collateral veins on retrograde venograms. The sensitivity and specificity of color Doppler sonography for revealing the nutcracker syndrome were assessed by analyzing pressure gradients in combination with the venograms, which were used as the gold standard. RESULTS: Twenty-one nondistended left renal veins were seen, including 19 (43%) without collateral veins or hypertension and two (5%) with collateral veins but without hypertension (long-term nutcracker syndrome). The 23 distended left renal veins included seven without collateral veins or hypertension and one with hypertension but without collateral veins (early nutcracker syndrome). The remaining 15 distended left renal veins with collateral veins included 11 (25%) with borderline hypertension (partially compensatory status of the syndrome) and four (9%) with hypertension (noncompensatory status of the syndrome). The sensitivity and specificity of color Doppler sonography for revealing the nutcracker syndrome were 78% and 100%, respectively, when color flow in collateral veins was included in the diagnostic criteria. CONCLUSION: The nutcracker syndrome can exist in either nondistended or distended left renal veins. However, normal flow also can exist in distended left renal veins. The ability of color Doppler sonography to reveal color flow in collateral veins is useful for the noninvasive diagnosis of the nutcracker syndrome.

Adolescent↗